General Note
IRC reserves the right to make changes in product specification without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of going to print. A subsidiary of
TT electronics plc
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
AL Series
• ±1% tolerance
• 5 watts to 50 watts
• 0.1 ohm to 180K ohm*
• Non-inductive winding available
• High thermal conductivity cores available
• Lead Free RoHS Compliant Construction
*Values down to .01 ohms available. Contact factory with special applications.
Chassis Mounted Power
Wirewound Resistor
Electrical Data
IRC/SX
Style**
MIL
Equivalent
Power Rating @25°C (watts) Resistance (ohms)
IRC/SX MIL Min. Max. Max. MIL
AL-5 RE-60G 7.5 5 0.1 16K 3.32K
AL-10 RE-65G 12.5 10 0.1 25K 5.62K
AL-25 RE-70G 25.0 20 0.1 55K 12.1K
AL-50 RE-75G 50.0 30 0.1 180K 39.2K
*All resistors have an operating temperature range of -55°C to +275°C. Derating is required for reduced chassis mounting area
and for high ambient temperatures.
**To order non-inductive styles add suffix N (e.g.:ALN-5). (Divide Max. Res. Values by styles available with extended resistance
and tolerance ranges; contact factory.
Power Rating:
5 to 50 watts depending upon style. 275°C maximum hotspot at 25°C ambient. Conforms to MIL-R-18546.
1% maximum ∆R in 1000 hour load life. Proper heat sinks are as follows:
4 x 5 x 2 x 0.040 aluminum chassis - AL-5 and AL-10
5 x 7 x 2 x 0.040 aluminum chassis - AL-25 and AL-50
Construction:
Windings are "controlled stress" wound on ground ceramic cores. Terminations are of welded construction.
Terminals are electronically welded to the end caps for maximum strength and electrical continuity. A high
temp. silicone encapsulation is used to mold the wound assembly within the anodized
Standard Temperature Coefficient of Resistance:
<1 ohm = ±90 ppm
≥1 ohm to <10 ohms = ±50 ppm
≥10 ohm = ±20 ppm
AL Series Issue August 2008 Sheet 1 of 2
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Physical Data
Sample Part No.
IRC Type
AL
Power
10, 25, 50
Range
Tolerance
J = ±5%; F = ±1%; D = ±0.5%; B = ±0.1%
Lead Free Construction
Ordering Data
AL - 10 10RD F LF
Chassis Mounted Power
Wirewound Resistor
Dimensions (inches and (mm))
Style
Tol.
(metric)
AL-5
A
±0.005
±0.1
0.444
(11.28)
B
±0.005
±0.1
0.490
(12.45)
C
±0.031
±0.8
0.600
(15.24)
D
±0.062
±1.6
1.035
(28.58)
E
±0.015
±0.4
0.334
(8.48)
F
±0.015
±0.4
0.646
(16.41)
G
±0.015
±0.4
0.320
(8.13)
H
±0.010
±0.25
0.065
(1.65)
J
±0.010
±0.25
0.140
(3.56)
K
±0.010
±0.25
0.078
(1.98)
L
±0.005
±0.1
0.093
(2.36)
M
±0.015
±0.4
0.078
(1.98)
N
±0.005
±0.1
0.050
(1.27)
AL-10 0.562
(14.27)
0.625
(15.88)
0.750
(19.1)
1.375
(34.93)
0.430
(10.92)
0.800
(20.3)
0.400
(10.2)
0.075
(1.91)
0.190
(4.83)
0.093
(2.4)
0.093
(2.4)
0.102
(2.59)
0.086
(2.18)
AL-25 0.719
(18.26)
0.781
(19.84)
1.062
(26.97)
1.938
(49.23)
0.530
(13.46)
1.080
(27.43)
0.560
(14.22)
0.085
(2.16)
0.260
(6.6)
0.172
(4.37)
0.125
(3.18)
0.115
(2.92)
0.086
(2.18)
AL-50 1.563
(39.7)
0.844
(21.44)
1.968
(49.99)
2.781
(70.64)
0.615
(15.62)
1.140
(28.96)
0.615
(15.62)
0.085
(2.16)
0.300
(7.62)
0.196
(4.97)
0.125
(3.18)
0.107
(2.71)
0.086
(2.18)
J
E F
H
GD
B
M
C
AK
N
L
AL resistors are rated to operate with a 275°C maximum hotspot under full rated power
at 25°C ambient. They must be derated for higher ambient temperature per "Wattage
vs. Ambient Temperature Derating Curve."
AL Series Issue August 2008 Sheet 2 of 2
Power Derating Curve
120
100
80
60
40
20
025 75 125 175 225 275
Percent of Power Rating
Ambient Temperature (°C)
325
Aluminum Chassis
A
B
C
